While we talk, Williams is working at the counter in his brother's convenience store in Lafayette, Louisiana. Williams is the singer, songwriter and piano-key accordion player who leads Nathan and the Zydeco Cha-Chas, but he helps out at the store whenever he's home. Lately, though, Williams hasn't been there much. His band has just released its third record, Your Mama Don't Know (Rounder), and is touring farther and farther from Louisiana. But on this afternoon, he's back selling six-packs and making change for the pay telephone. His sister-in-law listens over his shoulder to the interview and gets her two cents in when she feels Nathan isn't saying enough. The 27-year-old Williams and his band are among the youngest members of zydeco's second generation. They follow the breakthrough that Clifton Chenier, Rockin' Dopsie, Rockin' Sidney, Buckwheat Zydeco and others forged in the early Eighties. Williams and others in this younger generation--Terrance Simien, Wayne Toups, C.J. Chenier--have taken a once-obscure Louisiana dance music to the far corners of the planet.

The linguistic history of zydeco makes for an interesting tale. Once known as "la la," zydeco music was given its current name--a Creole word meaning "snap beans"--by the late king of zydeco, Clifton Chenier. When Chenier started out in the Fifties, the music was derisively known as "chanky-chank" because of its insistent, repetitive beat. Based on a mix of Afro-Caribbean calypso rhythms and many of the song structures of American blues, zydeco also draws inspiration from Sixties R&B, Cajun fiddling and European polka music.

The musical backgrounds of this latest generation of zydeco players have added other influences, most notably rock 'n' roll, to this already varied musical gumbo.

Unlike their mentors, the young bucks of zydeco like Williams--each one an accordion player, vocalist and bandleader--sell records and have become full-time musicians almost overnight. Williams and the band are on the edge of turning that crucial quitting-the-day-job corner. "I help out here when I can," Williams says, ringing up a pack of Marlboro Lights with a polite "please" and "thank you." "But we've been on the road so much that the other guys have had to quit their jobs here. That's okay with them, though. We'd rather be on the road playin' day zydeco," he says in his French-accented English.

Williams is a tall, soft-spoken man who prefers shades and a cowboy hat (a la another zydeco pioneer, Boozoo Chavis), and his zydeco is, like many of his contemporaries, a mixture of the traditional and the modern. Flecked with new quirks like rock 'n' roll drumming and a smooth, Stax-soul vocal style, Williams' music also sticks with traditional zydeco forms like the polka and traditional zydeco instruments like the rubboard. Catering to both old and new, Williams sings in both French and English. But he admits that when he's not in Louisiana or Quebec, he sticks mostly to anglais.

What Williams and the other young zydeco players have done for the music is to bring it a wider, younger audience. Their aggressive style makes it easy for rock 'n' rollers to relate. Williams' musical background is a good illustration of where zydeco's latest generation gets its inspiration.

"I heard Cajun and zydeco music all the time while I was growing up," says Williams. "Why, in 1974, I used to sneak in the back of the Casino Club in my hometown of St. Martinville to see Clifton Chenier. But I also listened to the radio. I loved the Commodores, Al Green, Bobby `Blue' Bland, you know, the works!"

Those "works" are what gives Williams' zydeco originals their kick. Still close to his mentor and teacher Buckwheat Zydeco (Stanley Dural), Williams and his band have been at it for four years. A tight, rhythm-happy ensemble, the Cha-Chas include guitarists James Benoit and Dennis Paul Williams, tenor saxman "Doctor" John Wilson, bassist Russell Benoit, rubboard player Mark Williams and drummer Johnny Batiste. The addition of the saxophone gives the group an unusual edge for a zydeco band. Live and on record, the Cha-Chas still have a few rough edges, but they continue to improve with each disc.

Taking its name from a famous Clifton Chenier tune, "Zydeco Cha-Cha," the band began its musical journey back at El Sid O's, a Lafayette club that Nathan's brother Sid bought and named after himself. It was there in 1987 that Rounder Records producer Scott Billington first saw the Cha-Chas. After inking a record deal, the Cha-Chas and Billington returned to El Sid O's to record the group's first album, Zydeco Live. The band's first studio record, Steady Rock, was cut a year later. Both albums have done extremely well in the U.S. and Europe. Because zydeco musicians tend on most songs to get into a rhythmic groove and stay there, the mark of the zydeco master is the ability to write a memorable melody. Williams, who writes all the band's material, is strong as both a lyricist and a tunesmith. All his original material is published by, you guessed it, his brother's El Sid O's Music-Happy Valley Music label. Of all the things Williams does with the band--and that includes leading the de rigueur four-hour marathon sets--his songwriting is the most crucial to its success.

"I want my albums to speak about so many things," Williams says. "Words mean a lot to me. I want my words to speak about truths. About how no matter what hits you, life must go on."

Although he's currently part of the younger generation in the zydeco family tree, Williams is one player who is already working on another.

"When I'm at home, my son plays with me. He plays drums and rubboard and he ain't bad for four years old."

Nathan and the Zydeco Cha-Chas will perform a free show at Hayden Square Amphitheatre on Thursday, June 13. Showtime is 6 p.m.

"I used to sneak in the back of the Casino Club in my hometown of St. Martinville to see Clifton Chenier."